I don't really think there are "dangerous" programming styles. You do have
ofcourse "ineffective" programming styles (such as using a horde of Part
operations and For loops to mimic C in Mathematica) and there are
"error-prone" programming styles (such as naming your favourite variable
ASDADS12231).
I think using Select on general structures(not just _List) is fairly safe;
do keep in mind though, that Select searches in all the levels of your
expression and you might get weird results because of this.
Orestis
"Detlef Mueller" <dmueller at mathematik.uni-kassel.de> wrote in message
news:9i068k$h0i$1 at smc.vnet.net...
> Hello,
>
> The Help Browser says:
>
> Select[list, crit] picks out all elements ...
>
> Now this works fin for other Haeders thal List
> too.
>
> Select[Expand[P], ! NumberQ[#] &] removes the
> absolute Part of the Poynomial P
> (in my Version).
>
> Is this a dangerous Way of Programming?
>
> Greetings
> Detlef
>